Leak Testing (R-1234yf)
Special Tools:
  • GE-41447 A/C Tracer Dye-Box of 24
  • GE-42220 Universal 12V Leak Detection Lamp
  • GE-43872 Fluorescent Dye Cleaner
  • GE-50078 Electronic Leak Detector
  • GE-50744 R-1234yf PAG Oil Injection Hose
  • GE-50745 R-1234yf POE Oil Injection Hose

Equivalent regional tools:Special Tools

Refrigerant Leak Testing

Technicians repairing or servicing motor vehicle air conditioning (MVAC) systems must be trained and certified by an Environmental Protection Agency (EPA) approved organization. Certification is obtained by passing an EPA approved examination. (http://www.epa.gov/ozone/title6/609/technicians/609certs.html)

Warning: Technicians must only use a SAE J2913 certified electronic leak detector when checking for leaks in an R-1234yf A/C refrigerant system. Other, non–certified, leak detection devices could serve as ignition sources in the presence of hydrocarbons or other flammable refrigerants. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

Warning: R-1234yf Proper Service Procedures Warning

Warning: R1234-yf is considered a mildly flammable refrigerant and proper refrigerant leak testing should be completed to ensure safe and proper operation. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

Caution: Leak detection shall only be done with the refrigerant that is specified for the system. Do not attempt to increase pressure of the A/C refrigerant system with shop air or another type of refrigerant. Failure to follow the above guidelines could result in damage to the vehicle or its components.

Note: General Motors vehicles are manufactured with fluorescent dye installed in the Air Conditioning (A/C) refrigerant system.

The fluorescent dye mixes and flows with the A/C compressor oil throughout the refrigerant system.

Note: The only time adding additional fluorescent dye is required is after flushing the A/C system.

Verifying some passive leaks may require using GE-50078 Leak Detector or a SAE J2913 leak detector, even though the refrigerant system contains fluorescent dye.

Fluorescent Leak Detection

Fluorescent dye will assist in locating any leaks in the A/C system.

  • Condensation on the evaporator core or the refrigerant lines may wash the compressor oil and fluorescent dye away from the actual leak. Condensation may also carry dye through the Heating Ventilation and Air Conditioning (HVAC) module drain.
  • Leaks in the A/C system will be indicated in a light green or yellow color when using the leak detection lamp.

    Use the leak detection lamp in the following areas:

    • All fittings or connections that use seal washers or O-rings
    • All of the A/C components
    • The A/C compressor shaft seal
    • The A/C hoses and pressure switches
    • The HVAC module drain tube, if the evaporator core is suspected of leaking
    • The service port sealing caps
    • The sealing cap is the primary seal for the service ports
  • Follow the instructions supplied with GE-42220 Leak Detection Lamp.
  • To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a rag and the approved GE-43872 Dye Cleaner.

Fluorescent Dye Injection

    Note: Use only fluorescent dye approved by General Motors.

  • Not all of the fluorescent dyes are compatible with all air conditioning oils. Some types of dye decrease the oil viscosity or may chemically react with the oil.
  • GE-41447 A/C Tracer Dye-Box of 24 can be poured directly into a removed A/C component.

    • Note: Do NOT overcharge the A/C system with dye.

  • If the A/C system has been repaired and oil is needed in the system, use either the GE-50744 R-1234yf PAG Oil Injection Hose or GE-50745 R-1234yf POE Oil Injection Hose.
  • Leak detection dye requires time to work. Depending upon the leak rate, a leak may not become visible for between 15 minutes and 7 days.
  • To prevent false diagnosis, thoroughly clean any residual dye from the service port with a rag and the approved GE-43872 Dye Cleaner.

Electronic Leak Detector – SAE J2913 Certified

Note: The electronic leak detector is only effective when sensor is within 3/8” of the component being checked. Placing the sensor inside the instrument panel outlets is not effective for checking evaporators; the sensor is too far from the evaporator and can be triggered (false signals) by materials used inside the HVAC module. The preferred method for inspecting evaporator for leaks is the presence of fluorescent dye or excessive compressor oil on the HVAC condensation drain tube.

Ensure that the vehicle has at least 15 percent of the specified refrigerant charge in the A/C refrigeration system in order to perform a leak test. Refrigerant Recovery and Recharging.

Note: Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

Follow the manufacturer instructions supplied with GE-50078 Electronic Leak Detector or a SAE J2913 certified electronic leak detector.